In the US, 26 million adults have either type 1 or type 2 diabetes (11% of the population), with Type 2 diabetes mellitus (T2DM) accounting for 90-95% of all cases. Additionally, 79 million individuals (35% of the adult population) have been estimated to have pre-diabetes. Epidemiologic studies suggest that 9 out of 10 cases of T2DM can be blamed on modifiable lifestyle behaviors that result in critical risk factors, with the major one being obesity. This pilot research study is intended to address the large and growing problem of diabetes, particularly among veterans, by examining the ability for systematic instruction on the use of the VA's MyHealtheVet (MHV) personal health record to better enable pre-diabetic obese veterans to adopt and adhere to more positive diet and physical activity. Specifically, veterans will receive instruction on the use of the track health function (THF) of MHV, which provides sophisticated interactive tools for maintaining food and activity journals and for entering and viewing measures of physiological health. Instruction will include how to concurrently track the lifestyle and physiological measures and how to infer cause-effect relationships. Study participants will also be instructed to use the secure messaging feature of MHV to regularly communicate with members of the research team in order to maintain participants' motivation in the program. A recent survey on veterans' use of MHV indicated that the THF has been mostly unused; thus its potential as a health self- management tool has been largely unexploited. In addition to the unique and powerful interactive features contained within MHV's track health functionality, the benefits of using MHV as a vehicle for instigating and promoting adherence to physical activity and diet lifestyle changes is believed to derive from its ability to address content and resources tailored to the needs of veterans, and thus elicit trust by this group through its in-group affiliation. The study goal is to recruit a sample of 100 obese pre-diabetic veterans attending primary care clinics at the Bruce W. Carter Miami VAMC. The inclusion criteria related to the pre-diabetes obesity criterion include HbA1C 5.7-6.4% and fasting plasma glucose 100-125 mg/dL (or oral glucose tolerance test 140-199 mg/dL; the exclusion criteria include currently following a weight loss diet or presence of diabetes mellitus. The intervention will be a single group, longitudinal, repeated measures design. Key outcome measures that will be obtained from participants at baseline and at three months include physical activity (measured with an accelerometer which will sample physical activity every minute for seven days), dietary intake, physical activity self-efficacy (exercise beliefs), diet self-efficacy (diet beliefs), intent to perform physical activity, and intent to adhere to diet. In addition, measures of health literacy, objective numeracy ability, and graphical literacy will be collected at baseline. During the baseline visit, blood pressure, pulse, weight, height, and abdominal circumference measurements will be obtained, and participants will also receive an accelerometer and instructions on its use. Participants will then return a week later, at which time the accelerometer data will be collected. They will receive a second two-hour training session on the THF of MHV, and then begin using MHV functions weekly as instructed, with secure messages sent weekly by the research team. At their three-month visit, participants will complete the post-intervention instruments and again receive an accelerometer, and will be asked to return the device a week later when the accelerometer data will be collected and an semi-structured exit interview will be conducted. This pilot research study is expected to demonstrate the utility of using the THF of MHV in terms of these participants' satisfaction in engaging with the THF, and in increasing their self-efficacy and intent to adhere to physical activity and diet, as well as their actual adherence to physical activity and diet. It is also expected to yield valuable data concerning the roles of numeracy ability, health and graphical literacy in the ability to use the THF effectively, as well as suggestions for redesigning this function to better meet the cognitive capabilities of a larger sample of users of MHV.